package Volume1.ch10;

import javax.swing.*;
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;

/**
 * 10-5:字体测试
 *
 * @Auther jacob
 * @Date 2020/8/16 01:42
 */
public class FontTest {
    public static void main(String[] args) {
        EventQueue.invokeLater(() -> {
            JFrame frame = new FontFrame();
            frame.setTitle("FontTest");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
        });
    }
}

class FontFrame extends JFrame {
    public FontFrame() {
        add(new FontComponent());
        pack();
    }
}

/**
 * A component that shows a centered message in a box
 */
class FontComponent extends JComponent {
    public static final int DEFAULT_WIDTH = 300;
    public static final int DEFAULT_HEIGHT = 200;

    @Override
    public void paintComponent(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        String message = "hello world";
        Font font = new Font("Serif", Font.BOLD, 36);
        g2.setFont(font);

        // 获取消息的尺寸
        FontRenderContext context = g2.getFontRenderContext();
        Rectangle2D bounds = font.getStringBounds(message, context);

        // 设置文字中心点
        double x = (getWidth() - bounds.getWidth()) / 2;
        double y = (getHeight() - bounds.getHeight()) / 2;

        // add ascent to y to reach the baseline
        double ascent = -bounds.getY();
        double baseY = y + ascent;

        // draw the message
        g2.drawString(message, (int) x, (int) baseY);
        g2.setPaint(Color.LIGHT_GRAY);

        // 基线
        g2.draw(new Line2D.Double(x, baseY, x + bounds.getWidth(), baseY));

        // 内接矩形
        Rectangle2D rect = new Rectangle2D.Double(x, y, bounds.getWidth(), bounds.getHeight());
        g2.draw(rect);

    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(DEFAULT_WIDTH, DEFAULT_HEIGHT);
    }
}
